rbd: move bumping img_request refcount into rbd_obj_request_submit() (4a17dadc) · Commits · 戴 / test

Commit ("rbd: use reference counts for image requests") added rbd_img_request_get(), which rbd_img_request_fill() calls for each obj_request added to img_request. It was an urgent band-aid for the uglyness that is rbd_img_obj_callback() and none of the error paths were updated. Given that this img_request reference is meant to represent an obj_request that hasn't passed through rbd_img_obj_callback() yet, proper cleanup in appropriate destructors is a challenge. However, noting that if we don't get a chance to call rbd_obj_request_complete(), there is not going to be a call to rbd_img_obj_callback(), we can move rbd_img_request_get() into rbd_obj_request_submit() and fixup the two places that call rbd_obj_request_complete() directly and not through rbd_obj_request_submit() to temporarily bump img_request, so that rbd_img_obj_callback() can put as usual. This takes care of img_request leaks on errors on the submit side. Signed-off-by:

Ilya Dryomov <idryomov@gmail.com> Reviewed-by:

Alex Elder <elder@linaro.org>

drivers/block/rbd.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -1618,11 +1618,17 @@ static bool obj_request_type_valid(enum obj_request_type type)
		}
		}

		static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);

		static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
		{
		struct ceph_osd_request *osd_req = obj_request->osd_req;

		dout("%s %p osd_req %p\n", __func__, obj_request, osd_req);
		if (obj_request_img_data_test(obj_request)) {
		WARN_ON(obj_request->callback != rbd_img_obj_callback);
		rbd_img_request_get(obj_request->img_request);
		}
		ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
		}

		@@ -2588,8 +2594,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,

		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);

		rbd_img_request_get(img_request);

		img_offset += length;
		resid -= length;
		}
		@@ -2723,10 +2727,9 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
		return;

		out_err:
		/* Record the error code and complete the request */

		orig_request->result = img_result;
		orig_request->xferred = 0;
		rbd_img_request_get(orig_request->img_request);
		obj_request_done_set(orig_request);
		rbd_obj_request_complete(orig_request);
		}
		@@ -2881,6 +2884,7 @@ static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
		fail_orig_request:
		orig_request->result = result;
		orig_request->xferred = 0;
		rbd_img_request_get(orig_request->img_request);
		obj_request_done_set(orig_request);
		rbd_obj_request_complete(orig_request);
		}

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